1. Field of the Invention
The present invention generally relates a biofilter for removing odorous air and a method for breaking down a pallet including plastic, paper, cardboard, and organic material to produce bio-gas, fertilizer, and water and removing odorous air generated during the production of the bio-gas, fertilizer, and water.
2. Description of the Prior Art
Traditional method of waste handing has been landfilling—a process of burying waste in a landfill. However, landfilling can cause environmental pollution discharges to the water and, as real estate values increase, is considered to be an unattractive use of land. Thus, current waste management strategies seek to limit the amount of refuse directed to landfills. Recycling and composting programs have become widely accepted for both commercial and residential waste to reduce the demands on landfills.
Anaerobic digestion presents an alternative for handling organic waste materials. The primary object of anaerobic digestion is the production of a mixture of bio-gas, which may be utilized as an energy source to generate electricity and/or heat. Any solid material remaining at the end of the anaerobic digestion process is typically disposed of by conventional landfilling or composted into soil amendment. Typically, plastic, paper, cardboard, and other non-organic material cannot be accepted into an anaerobic waste processing facility.
On such method is disclosed in U.S. Pat. No. 7,955,839. The method issued for breaking down a pallet including plastic, paper, cardboard, and organic material to extract organic material to feed into an anaerobic digester to produce bio-gas, e.g. bio-methane. The first step of the method is removing the cardboard, e.g. packaging material, from the paper and/or the plastic and the organic material. The next step of the method is separating the organic material from the paper and the plastic, e.g. plastic containers. The organic material is then fed to the anaerobic digester. Finally, the organic material is converted to the bio-gas, the fertilizer, and the water using the anaerobic digester. The paper and the plastic may be recycled
One such biofilter is disclosed in U.S. Pat. No. 6,337,203. The biofilter includes a housing having a top wall and a bottom wall. Side walls extends between the top wall and the bottom wall connecting the top wall with the bottom wall and defining chamber between the top wall the bottom wall and the side walls. The bottom wall of the housing defines at least one entrance disposed in communication with the chamber for transferring the odorous air into the chamber. A plurality of trays disposed in the chamber and attached to the housing. A filter media is disposed on each of the trays for removing odor from the odorous air in the chamber and produce a purified air. At least one sprinklers disposed in the chamber and attached to the housing for transferring water into the chamber of the housing to maintain the chamber of the housing in a predetermined humidity. A heater disposed in the housing of the chamber and attached to the top wall of the housing to maintain the chamber of the housing between a predetermined temperature. The top wall of the housing defines an exit disposed adjacent to the side wall of the housing for removing the purified air from the chamber of the housing.